/* clock example: frequency of primes */
#include <stdio.h>      /* printf */
#include <time.h>       /* clock_t, clock, CLOCKS_PER_SEC */
#include <math.h>       /* sqrt */

int frequency_of_primes(int n) {
    int i, j;
    int freq = n - 1;
    for (i = 2; i <= n; ++i) for (j = sqrt(i); j > 1; --j) if (i % j == 0) {
        --freq;
        break;
    }
    return freq;
}

int mainFrecuency() {
    clock_t t;
    int f;
    t = clock();
    printf("Calculating...\n");
    f = frequency_of_primes(99999);
    printf("The number of primes lower than 100,000 is: %d\n", f);
    t = clock() - t;
    printf("It took me %d clicks (%f seconds).\n", t, ((float) t) / CLOCKS_PER_SEC);
    return 0;
}